Embodiments of the present inventive concept relate to semiconductor devices, and more particularly to a high-voltage sawtooth current driving circuit adapted for use in semiconductor devices, wherein the high-voltage sawtooth current driving circuit is characterized by charge pump having reduced size.
In semiconductor devices, such as phase-change random access memory (PRAM) and resistive random access memory (RRAM), certain operations (e.g., write, read, and/or erase) may be performed in relation to memory cells using voltages or currents having a sawtooth waveform. Many of these sawtooth signals are generated with a voltage level higher than a power supply voltage (e.g., Vcc) supplied to the semiconductor device. In order to generate “high-voltage” signals (i.e., signals higher than the power supply voltage), charge pump circuits capable of boosting the external power supply voltage are commonly used. However, as the magnitude of a sawtooth current increases, the size of a conventional charge pump circuit increases proportionally, and the charge pump circuit ends up occupying a much larger area than is desired. Large charge pump circuit size inhibits overall efforts to miniaturize the constituent hardware in many types of portable host devices.
Since the output of conventional charge pump circuits is directly related to a sawtooth current driver and since the charge pump circuit must output a relatively high peak current for the sawtooth current, not only does the size of the charge pump circuit increase, but also the charge pump circuit consumes a large amount of instantaneous current.